In recent years, mobile electronic devices, such as smartphones, tablet PCs, digital cameras, MP3 players, e-books, etc., have been widely used. Mobile electronic devices are generally equipped with a battery. Batteries for mobile electronic devices are divided into a removable type and a non-removable type according to whether they can be replaced. When a removable battery installed within mobile electronic devices has been discharged, it may be replaced with a fully charged battery. Mobile electronic devices with a removable battery are advantageous in that the removable battery is easily replaced with another. Mobile electronic devices with a removable battery are turned off during the battery replacement. Mobile electronic devices with a non-removable battery do not need to replace their battery with another except under rare circumstances. Therefore, mobile electronic devices with a non-removable battery may experience a power-off situation less frequently than mobile electronic devices with a removable battery.